Sewing machine equipped with pulse generator

ABSTRACT

A sewing machine equipped with a pulse generating means capable of providing digitally coded signal pulses related to the angular position of the sewing machine main-shaft is disclosed. The total number of coded signals exceeds the number of angular position sensors employed. The preferred embodiment utilized two Hall effect devices to provide four binary coded signals responsive to the position of the sewing machine mainshaft.



1. In a sewing machine having stitch forming instrumentalities including needle bar actuating means including a main shaft operatively connected to means for controlling said stitch forming instrumentalities, and pulse generator means driven by said main-shaft and providing at least three successively different digitally coded signals related to preselected angular positions of said main shaft upon movement of said main-shaft in one direction of rotation for synchronizing said controlling means with said shaft.
 2. A sewing machine according to claim 1 wherein said signals are binary coded.
 3. A sewing machine according to claim 1 wherein said controlling means is a digital control means.
 4. A sewing machine according to claim 1 wherein said pulse generator means comprises a plurality of position sensing devices responsive to said actuating means and collectively providing a number of coded signals exceeding the number of said sensing devices.
 5. A sewing machine according to claim 1 wherein said pulse generator provides binary coded pulses related to the angular position of said main-shaft member and includes two sensor means and two position indicating means.
 6. A sewing machine according to claim 1 wherein said sensor means is a Hall device.
 7. A sewing machine according to claim 1 wherein said pulse generator for providing digitally coded pulses relating to the angular position of a rotating main-shaft member, comprises: a. a base member; b. permanent magnet means adapted to be affixed to said base member; c. a plurality of sensor means adapted to be mounted juxtaposition said permanent magnet means for providing signal pulses, said sensor means having two stable states; and d. a plurality of position indicating means carried by said rotating member, each having a stepped peripheral circumference cooperating with said sensor means for changing the state of said sensor means in accordance with preselected angular positions of said rotating member.
 8. A sewing machine according to claim 7 wherein said base member includes a portion at one end extending outwardly therefrom and said rotating member further includes a circular shaped disc mounted thereon and adapted to cooperate with said outwardly extending base member portion. 